Method of granulating steel and forming wrought iron



Aug. 25, 1931. A. H. BEALE ET AL METHOD OF GRANULATING STEEL AND FORMINGWROUGHT IRON Filed July 19 lllrlll lI| l I l l I l llu INVENTORS A MPatented Aug. .25, 1931 4 UNITED STATES PATENT] OFFICE ADDISON H. BEALEAND ASTON, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOBS,

BY MESNE ASSIGNMENTS, TO A. M. BYERS COMPANY, OF PITTSBURGH, PENNSYL-VANIA, A CORPORATION OF PENNSYLVANIA METHOD OF GRANULATING STEEL FORMINGWROUGHT' IRON Application filed July 19,

Our invention relates to the Aston process of making wrought iron, such,for example, as set forth in several United States patents of JamesAston, such as No. 1,370,507, granted March 8, 1920, for method ofmaking wrought iron pipe; No. 1,412,823, granted April 18, 1922, formethod of making wrought iron; and No. 1,469,373 granted October 2,1923, for manufacture of wrought 1o 11011.

steel-making process is poured into a slag bath and shotted orgranulated by reason of the temperature difference between the bath ofslag and the steel poured in. The granules descending through the slagbath form a ball in the bottom by the welding together of the granulatedportions. In the early work on this process, congo siderabl'e diflicultywas encountered in obtaining uniform balls of the desiredcharacteristics.

In long study and experimenting in connection therewith, we havediscovered that to obtain the desired results definite relations shouldbe maintained, not only between the'temperature of the steel poured inand the temperature of the slag bath, but also as regards the depth ofthe slag bath, the total weight or mass of slag relative .to the totalweight of metal poured in, the height of the falling stream, thethickness of the. stream, and the time consumed for the shottingof aiven weight'of metal.

11 such experimenting we have found that in order to allow properrelease of the oxides and ases from the granules and their absorptlon bythe slag bath, which is of great importance in order ,to obtain thedesired grade and uniformity of the wrou ht iron 7 ball, the depth ofslag at the start of t e pouring operation should be not less than 18 or20 inches, and is preferably 3 or 4 feet. The pouring spout or nozzle ofthe receptacle containing the molten product of the steel-makingoperation should be more than '6 feet above the level of the slag, andis preferably 10 to 12 feet abovethat level.

We :have also found that to give the best results the total volume ofslag should be at In this process, the molten product of a 1928. SerialNo. 294,040.

and if the stream is too thick or large, the

metal is not properly shotted.

The above limits have, been foundafter long and careful study andexperimenting, and are highly important in obtaining improved anduniform results.

In the drawings,

Figure 1 is a plan view showing one form of crl'eceptacle for carryingout our invention; an

Figures 2 and 3 are vertical cross-sections of the same on the linesIIII and III-III,

res ectively, of Fig. 1.

n the drawings, which show a preferred form of shotting cup orreceptacle, 2 is an iron or steel shell wh1ch may be either cast or ofwrought material. converges downwardly to a slight extent on two sidescm and to a greater extent on the sides 66. The sides aa are preferablycast with hollow projections 3, 3 forming parts of trunnion pads andlifting lugs. The casting is preferably provided with an inwardlyprojecting flange 4 and is lined with a refractory material, such asfirebrick 5, covering the bottom and sides. The internal dimensions ofthe lined vessel are about as follows: at the bottom, 3 feet betweenthesides bb and 4 feet between the sides aa, with a depth of about 4% to5 feet.

In practice, the liquid slag is cured into this receptacle to a depth ofpre erably 3 to 4 feet, and the liquid steel is then poured in from aheight of 6 to 12 feet, and preferably about 10 to 12 feet. The pour isregulated so that the pouring rate isnot faster than 1 tons per minuteand the volume of slag is more than four times the volume of metalpoured into said slag.

This shell preferably In practice, we prefer to make the steel by theBessemer process, as we have found that in carrying out the process theconverter practice is of considerable advantage.

The advantages of our invention result from the quality of the ball orwrought iron mass resulting from the discovery of the proper depth andvolume of slag, and the desirable pouring height to obtain the best results; together with the rate of pour, which should not be beyond acertain volume per minute.

The vessel shown is, of course, merely an example.

Changes may be made in the form, size, etc., of the vessel, and'otherchanges may be made, without departing from our invention.

We claim:

1. In the making of wrought iron, the step consisting of pouring metalfrom a steelforming operation into and through a bath of puddle slag ofa depth greater than 18 inches.

2. In the making of wrought iron, the step consisting of pouring metalfrom a steelforming operation into and through a bath gf puddle slag ofa depth of about 3 to 4 eet.

3. In the manufacture of wrought iron,

the step consisting of pouring metal into a slag bath from a height ofnot less than 6 feet above the slag level through a bath of puddle slagof a depth greater than eighteen inches. 7

4. In the manufacture of wrought iron, the step consisting of pouringmetal into a slag bath from a height of 10 to '12 feet above the slaglevel through a bath of puddle slag of a depth greater than eighteeninches.

5. In the manufacture of wrought iron, the step consisting of pouringthe molten product of a steel-making process into a slag bath in astream at a rate not faster than one ton in 1 minutes.

6. In the manufacture of wrought iron, the step consisting of pouring astream of the molten product of a steel-making process into a slag bothat a rate of about 2 minutes per ton.

7. In the manufacture of Wrought iron, the step consisting of pouringinto a bath of puddle slag the product of a steel-making operation to anamount not more than onefourth the volume of the slag.

8. In the manufacture of wrought iron, the step consisting of pouringsteel into a bath of puddle slag of a depth of more than 18 inches, andrestricting the volume of steel poured into less than one-fourth thevolume of the slag.

9. In the manufacture of Wrought iron, the step consisting of pouringinto the bath of puddle slag the product of a steel-making process at arate not greater than one ton in 1 minutes and to a total amount lessthan our hands.

ADDISON H. BEALE. JAMES ASTON.

